Assessments of Jiroft Concrete Arc Dam foundation Displacements by Use of Extensometers Data

Document Type : Original Article

Authors

1 Associate Professor, Department of Engineering Geology, Tehran University

2 Office of Water Supply Facilities Operation, Water Resource Management Company, Tehran, Iran.

Abstract

Safe operation of dam has been based on three factors of structural integrity of dam, monitoring of dam and emergency preparedness. Instrumentation and data acquisition by instruments installed in different parts of the structure is one of the methods of monitoring. Jiroft Dam is an arch dam, that its extensometers data set has been used in order to understand the behavior of dam foundation during 20 years period of operation. The dam is 40km north-east of the city of Jirof, has been constructed on the Oligomiocene limestone. Jiroft Dam’s extensometers are from multi-rode type and have a maximum depth of 40m. The extensometers have been installed in the both side of upstream and downstream. Foundation displacements are affected from the reservoir loading and its water level. Foundation uplift in upstream and foundation subsidence in downstream are proportional to the reservoir water level variation. Moving average function used in order to eliminate short-term effects of annual changes in the water level. The highest values of uplift in upstream and subsidence in downstream occurred in the middle block and are about 8 and 3 mm, respectively. Downstream side of some blocks show a subsidence with constant small rate of about 0.1 mm/year. It is necessary to regularly dam monitoring considering continues constant rate of subsidence in mentioned blocks.

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اداره کنترل و پایداری سد جیرفت، 1390. گزارش رفتار نگاری سد جیرفت، شرکت سهامی آب منطقه‌ای کرمان. وزارت نیرو.
باباخانی، ع.ر. و همکاران، 1371. نقشه زمین‌شناسی ورقه سبزواران، نقشه‌های زمین‌شناسی ایران سری 1:250000. سازمان زمین‌شناسی و اکتشافات معدنی کشور، وزارت صنایع و معادن.
شهرکی قدیمی، ع.، 1370. نقشه زمین‌شناسی و شرح زمین شناسی ورقه اسفندقه، نقشه‌های زمین‌شناسی ایران سری 1:100000. سازمان زمین‌شناسی و اکتشافات معدنی کشور، وزارت صنایع و معادن.
Ahangari K., Noorzad A., 2010, Use of casing and its effect on pressure cells. Mining Science and Technology, 20(3): 384-390.
ASCE, 2000, Guidelines for instrumentation and measurements for monitoring dam performance. Task Committee on Instrumentation and Monitoring Dam Performance, American Society of Civil Engineers, pp. 712.
Biederman R., 1985. Dam safety in Switzerland, Swiss Dams – Monitoring and Maintenance. Swiss National Committee on Large Dams, Switzerland.
Chanson H., 2009. Embankment Overflow Protection Systems and earth Dam Spillways, In: Dams: Impacts, Stability and Design, Editors: Walter P. Hayes and Michael C. Barnes, Chap 4, pp. 101-132.
Kamali B.H., Ahangari K., Hosseini Shirvani M., 2012. Displacements Prediction in Double-Arch Dam Rock Abutment Using SPSS Software Based on Extensometer Readings Case study: Karun 4 Concrete Dam. Iran Research Journal of Applied Sciences, Engineering and Technology 4(22): 4607-4616.
Lombardi G., 2004. Advanced Data Interpretation for Diagnosis of Concrete Dams, Structural Safety Assessment of Dams. CISM International Centre for Mechanical Sciences, Udine, Italy.
Londe P., 1987.The Malpasset Dam Failures. Engineering Geology, 24:295-329.
Mirghasemi A.A., 2006.  Karkheh Dam Instrumentation System-Some Experiences, Geotechnical News, 24(1): 32-36.
Pougatsch H., Müller R.W., Kobelt A., 1998. Water alarm concept in Switzerland". Proceedings of the International Symposium on new Trends and Guidelines on Dam Safety, Barcelona, Spain, Berga ed.. Balkema, Rotterdam, pp. 235-242.
Rogers J.D., 2006. Lessons learned from the St Francis dam failure. Geostrata, 6 (2): 14-17.
Seed H.B., Duncan J.M., 1987. The Failure of Teton Dam. Engineering Geology, 24:173-205.
Sohrabi-Bidar A., Noorbakhsh S.M.M, Amin-Nejad M., 2011. On Accuracy of inclinometers measured data in Sabalan Dam, Iran. Proceedings of 79th Annual Meeting of International Commission on Large Dams, 29 May– 3 June, Lucerne,Switzerland.
Sohrabi-Bidar A., Noorbakhsh S.M.M., Imanshoar F., 2010. State of Stress on the Karkheh Dam using Instrumentation Data. 78th Annual Meeting of the International Commission on Large Dams, 23 – 26 May, Hanoi, Vietname.
Sugimura Y., Miura S., Konagai K., 2001. Damage to Shihkang dam inflicted by faulting in the September 1999 Chi-Chi earthquake. In: Proc. Workshop on Seismic Fault-induced Failures, ed. Konagai et al., Univ. of Tokyo, Japan.